On the occurrence of Rhomboidella prideaux (Leach, 1815) (Mollusca : Bivalvia : Mytilidae) in the eastern Mediterranean

2006·3.2 MB·English

by  Bilal Özturk

THE VELIGER
© CMS, Inc., 2006
The Veliger48(3):215-219 (November2, 2006)
On the Occurrence of Rhomboidella prideaux (Leach, 1815)
(Mollusca: Bivalvia: Mytilidae) in the Eastern Mediterranean
BILAL OZTURK,* JEAN-MAURICE POUTIERS,** MESUT ONEN,* and ALPER DOGAN*
*Ege University, Faculty of Fisheries, Department of Hydrobiology, 35100 Bornova, Izmir, Turkey
(e-mail: [email protected], [email protected], [email protected])
**Museum National d'Histoire Naturelle, Departement Systematique et Evolution, Unite Taxonomie et Collections
(Mollusques), Case Postale N°51, 55 rue de Buffon, F-75231 Paris cedex 05, France
(e-mail: [email protected], [email protected])
Abstract. In a study performed in 2000 on the benthic fauna inhabiting the Turkish coasts ofthe Aegean Sea, a small
less known Mytilidae species, Rhomboidella prideaux (Leach, 1815), which has not been reported from the eastern
Mediterranean so far, was found. In the present study, the taxonomie, ecological and distributional aspects ofthis species,
based on the material collected from the Aegean Sea and the eastern coast of Sicily, are provided.
INTRODUCTION Dimensions were measured using an ocular microme-
ter. Species description and morphological terminology
Rhomboidella Monterosato (1884:13) is one ofseventeen follow Cox (1969), amended by Ockelmann (1962, 1983)
genera of Mytilidae having representatives in the Medi- for early stages of development. As usual for Mytilidae,
terranean Sea (Sabelli et al., 1990). The genus includes dimensions were defined as follows: when ventral margin
only one Mediterranean species, which is an epibenthic is placed horizonally, length is the maximum size of
form, living attached to the substrate with its byssal valves measured according to that direction, and height
threads. Although some Mediterranean species of Mytil-
along a perpendicular direction.
idae (for example some species ofMytilaster) are distrib- The specimens (one specimen and a valve) are depos-
uted in environments showing greatly reduced levels of ited in the Department of Hydrobiology (Ege University,
salinity (Oztiirk et al., 2002) Rhomboidella prideaux Turkey). Additionally, series housed in the Museum Na-
(Leach, 1815) appearstobe astrictly marine species. This tional d'Histoire Naturelle (MNHN) Paris, were studied
tiny species is found mainly along the European and Af- by one of us (J.M.P.) for comparision. This additional
rican co&asts of the Atlantic Ocean (Berkeley, 1827; material was recently collected by diving and dredging
Forbes Hanley, 1849; Tebble, 1966; Segers, 2002) and MNHN
during a sampling campaign conducted by in the
in the western Mediterranean Sea (Van Aartsen et al., Gulf of Catania, eastern Sicily.
1984; Salas, 1996; Giannuzzi-Savelli et al., 2001). Here,
we report the species from the eastern Mediterranean ba- RESULTS and DISCUSSION
sin for the first time.
The present study provides new locality records for R. Rhomboidella prideaux (Leach, 1815)
prideaux and gives additional information about its ecol-
ogy and general distribution. Modiolaprideaux Leach, 1815:35.
MATERIALS and METHODS Synonyms: Modiola rhombea Berkeley, 1827:229, pi. 18,
fig. 1. Modiola asperula Wood, S., 1840:252 (nomen nul-
In the framework of a research realized in 2000 to deter- lum); 1851:64, pi. 8, fig. 8.
mine the benthic fauna distributed along the Aegean
coasts of Turkey, samplings were carried out at 314 sta- Other references: Modiola prideauxiana, Brown, 1827:
tions in depths ranging from 5 to 200 m. Samples were 3, pi. 39, fig. 17; Crenella rhombea, Forbes & Hanley,
RA
collected by the Hippocampus, using a dredge cap- 1849:208-209, pi. 45, fig. 3; Rhomboidella rhombea,
turing a volume of almost 30 dm3 Material was sieved Monterosato, 1884:13; Modiolaria (Rhomboidella) rhom-
with 0.5 mm mesh and fixed in 4%. formaldehyde. In the bea, Dall, 1898:805; Winchworth, 1932:240; Crenella
laboratory, samples were sorted under a stereomicroscope {Rhomboidella) prideaux, Bowden & Heppell, 1966:103.
and preserved in 70% ethanol. During the research, spe- 115; Crenella prideauxi, Tebble, 1966:48-49, fig. 19b &
ciemens of R. prideaux were found at only one station 23; Solamen (Rhomboidella) pridaux(i), Soot-Ryen.
located in the southern part ofthe Aegean Sea (Figure 1). 1969:276; Solamen (Rhomboidella) prideauxi, Bruschi et
Page 216 The Veliger, Vol. 48, No. 3
Figure 2. Rhomboidellaprideaux (Leach, 1815), left valve: A)
from the outside, B) from the inside.
rhomboidal in outline. Shape very convex, becoming
more or less laterally compressed posterodorsally. Byssal
gape poorly developed, a narrow to obsolete slitjust an-
terior to mid-ventral margin ofthe valves. Umbones pro-
Figure 1. Map of the study area with location ofthe sampling sogyrate, prominent and nearly terminal. Anterior margin
site where Rhomboidella prideaux was found. short, strongly convex, not extending beyond the umbo-
nes. Ventral margin long and straight ornearly so (weakly
convex injuvenile stages, tending to be slightly depressed
al., 1985:48; Rhomboidellaprideaux, Sabelli et al., 1990: in the middle in mature specimens). Posterior margin
283. large and widely rounded, becoming less convex towards
the dorsum. Posterodorsal margin long and slightly
Material examined: West of Bodrum Peninsula, Turkey
arched, oblique in relation to ventral margin, forming a
(see Figure 1), 36°56'45"N-27°16'32"E, 31 m, 20th Sep-
rounded obtuse angle with posterior margin.
tember 2000, temperature 22.0°C, salinity 39.1 ppt, dis-
Outer surface ofvalves covered with numerous, dense-
solved oxygen concentration 4.97 mg/L, sandy substrata
mm ly set radial riblets, slightly diverging on posterodorsal
wmimth algae fragments, one specimmmen (1.4 mlomng, 1.2 and posteroventral areas, and crossed over by concentric
high), and a left valve (3.0 long, 1.9 high)
ridges. Radial riblets rounded, about as wide as their in-
(Figures 2, 3). tervals, increasing in number with growth by branching
GulfofCatania, eastern Sicily (M.N.H.N., 1990), from
or intercalation. Concentric ridges more widely spaced
North to South: Aci Trezza, Capo Mulini, 37°34.5'N-
15°11.9'E, 60-90 m, 5 left valves, 4 right valves; same
region, 37°34.5'N-15°20.0'E, 90-120 m, 2 right valves.
Brucoli, Capo Campolato, 37°17.8'N-15°12.8'E, 40-
60 m, right valve; same region, Cozzo dei Turchi,
I
37°17.7'N-15°09.8'E, 15-20 m, 2 left valves: same re-
gion, Brucoli Bay, 37°17.3'N-15°11.7'E, 3-9 m, sand
bottom with Posidonia, 1 left valve, 1 right valve; same
region, off Monte Amara, 37°16.5'N-15°13.5'E, 22-25
m, 2 left valves, 2 right valves.
mm
Description: Shell very small (up to about 3.5 long),
moderately thin for its size, equivalve, well inflated and
strongly inequilateral; rounded triangular to obliquely Figure 3. Rhomboidella prideaux, living specimen.
B. Ozturk et al., 2005 Page 217
than radial riblets, raised and sharp, most prominent in characters of this species and introduced the new genus
later growth stages, giving the shell periphery adecussate Rhomboidella for it, true identity and diagnostic features
aspect. Umbonal area with distinct nepioconch and prod- of R. prideaux have been poorly understood, during the
issoconch. Nepioconch large (about 680 to 700 |xm long), following 100 years, as stated by Van Aartsen et al.
rounded-oblique in outline, sculptured with numerous, (1984:58). As a consequence, the systematic position and
conspicuous, incised concentric lines. Prodissoconch nomenclatural status of R. prideaux has much varied in
large-sized (about 240 |j,m long), ratherconvex, D-shaped literature up to recent years. On the assumption that the
in outline, slightly more rounded anteriorly than posteri- species name prideaux was incorrect (as non latinized),
orly, with a narrow and somewhat flattened marginal area Leach's name has long been either variously emended (as
(corresponding to prodissoconch II); surface of prodis- prideauxi, prideauxii, or prideauxiana), or even rejected
soconch dull white, roughened by minute dense granu- by different authors. The opinion of major authors ofthe
lations. Periostracum very thin, adherant, smooth and XlXth century English school (for example Forbes &
transparent, resulting in a somewhat glossy and iridescent Hanley, 1849; Jeffreys, 1863) in the use of Berkeley's
aspect to the outer shell surface. Shell translucent greyish name rhombea, seemed a determining factor in that sit-
white in colour, under the pale straw-coloured periostra- uation, until Bowden & Heppell (1996:103, 115) gave
cum. good reasons to reinstate prideaux for the species. How-
Ligament inframarginal, not strong, brownish yellow ever, many authors still use rhombea or prideauxi (e.g.,
in colour, extending along posterodorsal margin to about Poppe & Goto, 1993; Salas, 1996).
two-thirds the distance from umbo to posterodorsal angle; Although the shell form and hinge ofR. prideauxdiffer
resilial ridge deeply inset, very thin, not pitted. Hinge completely from those of the genus Crenella Brown.
with a thickened process forming two poorly separated 1827, Rhomboidella has been often placed in Crenella as
denticles under the beak with tiny, irregular transverse a subgenus. In addition, Rhomboidella was included in
ridges. Shell margin smooth for a short distance just an- the Solamen as a subgenus by some other authors as well
terior to the beak. Posterior part of hinge line bearing a (Soot-Ryen, 1969; Bruschi et al., 1985). This varying ge-
series of small granules along and behind the otherwise neric allocation reflects the poorunderstanding ofthe spe-
smooth ligamental margin; size of these granulations in- cies and of its genus, as well as its frequent confusion
creasing progressively from umbonal area to posterodor- with other mytilid species. For instance, authors dealing
sal angle, where normal crenulations ofthe valve margins with Mediterranean fauna (Parenzan, 1974:55) have fol-
begin. lowed Nordsieck (1969:30-31), who added to the con-
Interior of shell somewhat glossy and subnacreous, fusion in considering R. rhombea and R. prideaux as dis-
nearly smooth, with the outer sculpture showing through. tinct species, and in distinguishing Crenella arenaria
Muscle scars and pallial line indistinct. Internal margins Monterosato, 1875 at subspecies level withinR.prideaux.
finely crenulate in accordance with the outer sculpture. This situation may have partly arisen from the difficulty
of detailed examination of these tiny shells, since their
Taxonomic status: Romboidella prideaux was first re- maximum size does not exceed a few millimeters. The
ported from southern England by Leach (1815:35), who outer sculpture ofthe shell is clearly distinct in specimens
briefly described it as Modiola prideaux but failed to il- of Crenella arenaria, owing to the absence ofradial rib-
lustrate it. A figure accompanying this short description lets in this species (Giannuzzi-Savelli et al., 2001:fig.
was provided much later (Leach & Gray, 1852:333, pi. 189, p. 115).
12, fig. 9). In the intervening years, the species in ques- A correct appraisal of the variability ofR. prideaux is
tion, still included in the genus Modiola, has been rede- also necessary for its unambiguous distinction from re-
scribed and figured by Brown (1827:3, pi. 39, fig. 17) lated species. This species varies in shell form and sculp-
under the emended name of M. prideauxiana, or as a ture. Shape may be variable in length, the posterodorsal
different species as M. rhombea by Berkeley (1827:229, angle well-marked to rounded and more or less obtuse.
pi. 18, fig. 1). Wood (1851:64, pi. 8, fig. 8) created M. Furthermore, the mid-ventral margin may be straight to
asperula for a Pliocene species from the Crag Formation somewhat depressed in adult stages. The comprehensive
of England, and this was generally considered as a syn- information and drawings provided by Tebble (1966:48-
onym of R. prideaux later on (Glibert & Van de Poel, 49, fig. 19B & 23) illustrate the variability of shell shape
1965:79). The species has been placed in other genera, in this species.
such as Crenella (Forbes & Hanley, 1849:208-209; The shell shape ofthe specimens from the Aegean Sea
Winckworth, 1932:240; Bowden & Heppell, 1966:103, and eastern Sicily are similar to shells from Algesiras
115; Tebble, 1966:48-49; Seaward, 1990:69), Modiolaria Bay, Spain (Van Aartsen et al., 1984:126, fig. 292). Some
[a junior synonym of Musculus (Dall, 1898:805; Lamy, variation in shape and sculpture may be related to ontog-
1937:7)], or Solamen (Soot-Ryen, 1969:276). eny. Concentric sculpture tends to be less developed in
Though Monterosato (1884:13) pointed out the struc- juveniles, and there is an allometry ofgrowth with a pro-
tural differences between the genus Modiola and the shell gressive reduction of the height to length ratio. This can
Page 218 The Veliger, Vol. 48, No. 3
be correlated with a fast growth of the posterior part of In the past, R. prideaux was reported from the Western
shell, the umbones being shifted from a submedian po- Mediterranean and in the Eastern Atlantic, from the Brit-
sition on the dorsal margin atnepioconch stage to amark- ish Isles and Ireland (Marshall, 1897) to West Africa. Re-
edly anterior one in the adult. cent data (Seaward, 1990; Smith & Heppell, 1991) show
that the northern limit of the species is in southern Eng-
Ecology and distribution: The Aegean Sea is an ecolog- land (from Margate, Kent, in the East, to the Sicily Is-
ically distinct part of the Mediterranean Sea due to its lands and the Bristol Channel in the West) and western
peculiar hydrographic characteristics. It is an area where Ireland (northwestern Connaught). In the South, it has
the brackish waters ofthe Black Sea (17%o) communicate been reported from Morocco to Santa Helena Island (Go-
with the saline waters of the Eastern Mediterranean Sea mez Rodriguez & Perez Sanchez, 1997), but its exact
(39%o). According to Kocatas & Bilecik (1992), great distribution is much uncertain because of recurrent con-
fluctuations exist among the ecological features such as fusion with similar Rhomboidella species. In that area, it
temperature, salinity and nutrients, in the southern Ae- certainly occurs in northern Morocco (Salas, 1996) and
gean Sea influenced by the Eastern Mediterranean Sea probably also in the northern oceanic islands ofMadeira
and in the northern Aegean Sea affected by the Black and the Canaries, where it co-occurs with R. canariensis
Sea. This ecological variation affects the flora and the (Odhner, 1931). It seems to be absent from the tropical
fauna. There are tropical as well as boreal molluscs, but coasts ofAfrica, where R. canariensis and R. obesa Ock-
most of the more than 300 bivalve species have an At- elmann, 1983 are rare and patchily distributed (Rolan &
lantic-Mediterranean distribution similar to that ofR. pri- Ryall, 1999; R. von Cosel, personal communication).
deoux. Easternmost records are the GulfofTunis, Tunisia (Wein-
Only scant information on the ecological requirements kauff, 1867:213, 299), Maltese Islands (Cachia et al.,
ofR. prideaux exists, and most deals with its depth range 1993) and the western Ionian Sea, in southern Italy (Par-
and preferred substrate. Previously, the species was only enzan, 1961:44) and Sicily (Gulf of Catania, new data).
reported from the Atlantic Ocean and from the Western In recent years, researches conductedin the eastern Ae-
Mediterranean region with a mean salinity of 35-36%o. gean Sea and its coastal lakes have contributed to the
However, the fact that the species has been found in the knowledge of the faunal diversity of that area. Thus,
southern Aegean Sea with a salinity value of 39%o, leads shortly after Mytilaster marioni (Locard, 1889) was re-
to the conclusion that this species tolerates environmental ported from Bafa Lake by Ozttirk et al. (2002), the dis-
conditions showing different levels of salinity, like many covery ofR. prideaux significantly increased the diversity
other species of Mytilidae. of the Mytilid fauna in this area.
Specimens ofR. prideaux live attached to the substrate
with their byssal threads, like most species of Mytilidae. LITERATURE CITED
Berkeley (1827:229) reported a specimen from Wey-
mouth adhering to a large mass of slate by its byssal Berkeley, M. J. 1827. A short account ofa new species ofMo-
threads. Nevertheless, living specimens of the species diola, andofthe animal inhabitants oftwo British Serpulae.
Zoological Journal 3:229-231.
have been reported from different types of substrates, in- Bowden, J. & D. Heppell. 1966. Revised list ofBritish Mollus-
cluding "coarse bioclasts, mud, rocks and gravel, sand, ca. 1. Introduction; Nuculacea-Ostracea. Journal of Con-
laminaria, algae" (Salas, 1996), and it is not excluded chology 26:99-124.
that it can lead an infaunal, superficially buried mode of Brown, T. 1827. Illustrations oftheRecentConchology ofGreat
life, as it has been hypothesized for the West African R. Britain and Ireland. W. H. & D. Lizars, Edinburg. XIV +
obesa Ockelmann (1983:102). The large size ofthe prod- Brusc1h2i5,pAp.., I. Ceppodomo, C. Galli & P. Piam. 1985. Carat-
issoconch and the reduction ofprodissoconch II, suggests terizzazione ecotipologica delle coste italiane. Catalogo dei
that development in R. prideauxis lecithotrophic andpos- Mollushchi conchiferi viventi nel Mediterraneo. ENEA,
sibly direct. Roma. XII + 111 pp.
This small sized Mytilid species may live in a range Cachia, C. C. Mifsud & P. M. Sammut. 1993. An Annotated
of depths on the continental shelf and possibly the upper Check-list of the Marine Mollusca of the Maltese Islands.
m Erste Voralberger Malacologische Gesellschaft, Rankweil.
sslooupteh.erAnltAheoguegahnitSeias,fiotunisdraetpoartdeedptfhroomfm3u1ch dieneptehre Cox,80L.ppR.. 1969. General features of Bivalva. Pp. 2-129 in R.
zones in the Western Mediterranean Sea and the Atlantic C. Moore (ed.). Treatise on Invertebrate Paleontology, Part
Ocean. For example, in the scope of her work on the N, Vol. 1 (of3), Mollusca6. Geological SocietyofAmerica,
Bivalve faunacollected during the "Balgim" and "Fauna Boulder & University of Kansas, Lawrence.
1" expeditions in the Alboran Sea, the Gibraltar Straits Dall, W. H. 1898. ContributionstotheTertiary FaunaofFlorida
with especial reference to the Miocene silex beds ofTampa
and the Ibero-Moroccan Gulf, Salas (1996) noted that the
andthe Pliocenebeds oftheCaloosahatchieRiver,including
species was found living at depths of 12-118 m. In the in many cases a complete revision of the generic groups
same work, R. prideaux was also found at the maximum treated of and their American Tertiary species. Part IV. I.
depth of 332 m, but only as empty valves. Prionodesmacea: NuculatoJulia. II. Teleodesmacea: Teredo
B. Oztiirk et al., 2005 Page 219
to Ervilia. Transactions ofthe Wagner free Institute ofSci- lusca: Bivalvia: Mytilidae) in Bafa Lake (Turkey), with a
ence, Philadelphia 3:571-947. redescription of the species. Hydrobiologia 485:123-131.
Forbes, E. & S. Hanley. 1849-1850. A History of the British Parenzan, P. 1961. Malacologia Jonica (introduzione alio studio
Mollusca, andTheirShells. Vol. 2. VanVoorst: London.557 dei molluschi del Jonio). Thalassa Jonica 4:3-183.
pp. Parenzan, P. 1974. Carta d'identita delle conchiglie del Medi-
GiannCuopzpziin-iS,avAe.llMia,rgR.e,llF.iP&usaCt.erBio,giA..2P0a0l1m.erAitl,anCt.eEdberleleo,coMn.- Poppet,erGr.aneTo.&VoYl..G2o.tBoi.os19T9a3r.as:EuTraorpaentaon.S2e7as7heplpl.s. Vol. 2 (Sca-
chiglie del Mediterraneo. Vol. 7. Evolver: Roma. 246 pp. phopoda, Bivalvia, Cephalopoda). Hemmen: Wiesbaden.
GlibeCrote,noMz.oi'&quLe.eVtraanngDeredPeoselco.ll1e9c6t5i.onLsedseBliTvnasltviituatfRososyiallesddeus Rola2n2,1Ep.p.& P. Ryall. 1999. Checklist of the Angolan marine
molluscs. Lista de los molluscos marinos de Angola. Resen-
Sciences Natureiles de Belgique. Memoires de lTnstitut as Malacologicas 10:1-132.
Royal des Sciences Natureiles de Belgique 78:1-105. Sabelli, B., R. Giannuzzi-Savelli & D. Bedulli. 1990. Catal-
Gomez Rodriguez, R. & J. M. Perez Sanchez. 1997. Moluscos ogoannotatedei Mollischi marinidel Mediterraneo.Libreria
Bivalvos de Canarias. Cabildo Insularde Gran Canaria, Las naturalistica bolognese: Bologna. 348 pp.
Palmas: 1-425. Salas, C. 1996. Marine Bivalves from off the Southern Iberian
Jeffreys, J. G. 1863. British Conchology. Vol. 2. Van Voorst: Peninsula collected by the Balgim and Fauna 1 expeditions.
London. 479 pp. Haliotis 25:33-100.
Kocatas, A. & N. Bilecik. 1992. Ege Denizi ve Canli Kaynak- Seaward, D. R. 1990. Distributions of the Marine Molluscs of
lari (Aegean Sea and its living resources). Su Uriinleri Ar- North West Europe. Nature Conservancy Council: Shrews-
astirma Enstitusu, Bodrum. 88 pp. bury.
Lamy, E. 1937. Revision des Mytilidae vivants du Museum na- Segers, W. 2002. On some shallow water marine molluscs of
ctihoynlailogdi'eHi8s1t:oi5r-e71N.aturelle de Paris (Suite). Journal de Con- SmithtM,hoelSlA.uzsMocr.ae.s&.NaGtDli.oornHiaealppMMeaulrsli.esu14m91s9:18o.4f-CS1hc0eo4ct.kllainsdtIonffoBrrmiatitsihonMSaerriinees
Leach, W. E. 1815. Zoological Miscellany: Being Descriptions
11:1-114.
Leacoohpf,siNWse..wAE.aSn&ydnJo.IpnsEt.iesrGeosrtfaiytnh.geA1Mn8oi5lm2la.ulsMsco.alVlooufls.Gcr2oe.rautNmoBdrBdiretirati:annLnAoiranredaonSngy.end- SootPP-paR.lyee2onn7,t1o-lT2o8g10y9,6i9nP.aRr.tSuCNp.,erMVfooalom.rile1y((oeMdfy.t)3i,)l,TirMaeocaletaliusResacofainn6e.IsnGqvueereot,lroeg1bi8rc1aa5tl.e
According to their Natural Affinities and Anatomical Struc- Society ofAmerica, Boulder& University ofKansas, Lawr-
ture. Van Voorst: London. VIII + 376 pp. ence.
Marshall, J. T 1897. Additions to "British Conchology." Jour- Tebble, N. 1966. British Bivalve Seashells. British Museum
nal ofConchology 8:338-372. (Natural History), London. 212 pp.
Monterosato, T A. 1884. Nomenclatura generica e specificadi Van Aartsen, J. J., H. P. M. Menkhorst & E. Gittenberger.
alcune conchiglie mediterranee. Virzi: Palermo. 152 pp. 1984. The marine Mollusca ofthe Bay ofAlgesiras, Spain,
Nordsieck, F. 1969. Die europaischen Meeremuscheln (Bival- with general notes on Mitrella, Marginellidae and Turridae.
via), VomEismeerbis Kapverden, Mittelmeerund Schwarz- Basteria. Suppl. 2:1-135.
es Meer. Fischer: Stuttgart. XIII + 256 pp. Weinkauff, H. C. 1867. Die Conchylien des Mittelmeeres, ihre
Ockelmann, W. K. 1962. Developmental types in marine Bi- geographische und geologische Verbreitung. Band. 1. Mol-
valves and their distribution along the Atlantic coast ofEu- lusca acephala. Fischer, Cassel. XIX + 307 pp.
rope. Pp. 25-35 in L. R. Cox & J. F Peake (eds.), Proceed- WincCkownocrhtohl,ogRy.1199:3221.1-T2h5e2.British marine Mollusca. Journal of
ings ofthe 1st European Malacology Congress: London. Wood, S. V 1840. A catalogue of shells from the Crag. Maga-
Ockelmann, W. K. 1983. Descriptions of Mytilid species and zine ofNatural History 6:241-253.
definition of the Dacrydiinae n. subfam. (Mytilacea-Bival- Wood, S. V. 1851-1857. A Monograph of the Crag Mollusca,
via). Ophelia 22:81-123. or. Descriptions of Shells from the Middle and Upper Ter-
Ozturk, B., J. M. Poutiers, H. M. Sari & M. Ozbek. 2002. On tiaries of the East of England. Part II. Bivalves. Paleonto-
the occurrence of Myulaster marioni (Locard, 1889) (Mol- graphical Society: London.